Azeotrope-like compositions of 1-chloro-3,3,3-trifluoropropane and a mono- or dichlorinated C1 or C3 alkane

ABSTRACT

Azeotrope-like compositions of 1-chloro-3,3,3-trifluoropropane and a mono- or dichlorinated C 1  or C 3  alkane have been discovered which are useful in a variety of applications including industrial cleaning, blowing agent and aerosol applications.

FIELD OF THE INVENTION

This invention relates to azeotrope-like mixtures of1-chloro-3,3,3-trifluoropropane (HCFC-253eb) and a mono- ordichlorinated C₁ or C₃ alkane. These mixtures are useful in a variety ofapplications including industrial cleaning, blowing agent and aerosolapplications.

BACKGROUND OF THE INVENTION

Fluorocarbon based solvents have been used extensively for thedegreasing and otherwise cleaning of solid surfaces, especiallyintricate parts and difficult to remove soils.

In its simplest form, vapor degreasing or solvent cleaning consists ofexposing a room temperature object to be cleaned to the vapors of aboiling solvent. Vapors condensing on the object provide clean distilledsolvent to wash away grease or other contamination. Final evaporation ofsolvent from the object leaves the object free of residue. This iscontrasted with liquid solvents which leave deposits on the object afterrinsing.

A vapor degreaser is used for difficult to remove soils where elevatedtemperature is necessary to improve the cleaning action of the solvent,or for large volume assembly line operations where the cleaning of metalparts and assemblies must be done efficiently. The conventionaloperation of a vapor degreaser consists of immersing the part to becleaned in a sump of boiling solvent which removes the bulk of the soil,thereafter immersing the part in a sump containing freshly distilledsolvent near room temperature, and finally exposing the part to solventvapors over the boiling sump which condense on the cleaned part. Inaddition, the part can also be sprayed with distilled solvent beforefinal rinsing.

Vapor degreasers suitable in the above-described operations are wellknown in the art. For example, Sherliker et al. in U.S. Patent 3,085,918disclose such suitable vapor degreasers comprising a boiling sump, aclean sump, a water separator, and other ancillary equipment.

Cold cleaning is another application where a number of solvents areused. In most cold cleaning applications, the soiled part is eitherimmersed in the fluid or wiped with cloths soaked in solvents andallowed to air dry.

Recently, nontoxic nonflammable fluorocarbon solvents liketrichlorotrifluoroethane, have been used extensively in degreasingapplications and other solvent cleaning applications.Trichlorotrifluoroethane has been found to have satisfactory solventpower for greases, oils, waxes and the like. It has therefore foundwidespread use for cleaning electric motors, compressors, heavy metalparts, delicate precision metal parts, printed circuit boards,gyroscopes, guidance systems, aerospace and missile hardware, aluminumparts, etc.

The art has looked towards azeotropic compositions having fluorocarboncomponents because the fluorocarbon components contribute additionallydesired characteristics, like polar functionality, increased solvencypower, and stabilizers. Azeotropic compositions are desired because theydo not fractionate upon boiling. This behavior is desirable because inthe previously described vapor degreasing equipment with which thesesolvents are employed, redistilled material is generated for finalrinse-cleaning. Thus, the vapor degreasing system acts as a still.Therefore, unless the solvent composition is essentially constantboiling, fractionation will occur and undesirable solvent distributionmay act to upset the cleaning and safety of processing. Preferentialevaporation of the more volatile components of the solvent mixtures,which would be the case if they were not an azeotrope or azeotrope-like,would result in mixtures with changed compositions which may have lessdesirable properties, such as lower solvency towards soils, lessinertness towards metal, plastic or elastomer components, and increasedflammability and toxicity.

Besides being useful in cleaning applications, fluorocarbons haveutility in the production of polyurethane and polyisocyanurate foam asfoam expansion agents or blowing agents. Traditionallytrichlorofluoromethane (CFC-11), dichlorodifluoromethane (CFC-12) and1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) have been the blowingagents of choice in the preparation of these foams.

Azeotropic or azeotrope-like compositions are potentially desirable inthe refrigerant art because they do not fractionate upon boiling orevaporation. This behavior is desirable because in the previouslydescribed vapor compression equipment with which these refrigerants areemployed, condensed material is generated in preparation for cooling orfor heating purposes and unless the refrigerant composition is constantboiling, fractionation and segregation will occur upon evaporation andcondensation and undesirable refrigerant distribution may act to upsetthe cooling or heating.

The art is continually seeking new fluorocarbon based azeotropicmixtures or azeotrope-like mixtures which offer alternatives for new andspecial applications for industrial cleaning, blowing agent and aerosolapplications. Currently, fluorocarbon-based azeotrope-like mixtures areof particular interest because they are considered to bestratospherically safe substitutes for presently used fully halogenatedchlorofluorocarbons (i.e., e.g., CFC-11, CFC-12, CFC-113). The latterhave been implicated in causing environmental problems associated withthe depletion of the earth's protective ozone layer. Mathematical modelshave substantiated that hydrochlorofluorocarbons, like1-chloro-3,3,3-trifluoropropane, have a much lower ozone depletionpotential and global warming potential than the fully halogenatedspecies.

Accordingly, it is an object of the present invention to provide novelenvironmentally acceptable azeotrope-like compositions which are usefulin a variety of applications including industrial cleaning, blowingagent and aerosol applications.

It is another object of this invention to provide azeotrope-likecompositions which are liquid at room temperature and which will notfractionate under conditions of use.

Other objects and advantages of the invention will become apparent fromthe following description.

SUMMARY OF THE INVENTION

The invention relates to novel azeotrope-like compositions which areuseful in a variety of applications including industrial cleaning,blowing agent and aerosol applications. Specifically the inventionrelates to compositions of 1-chloro-3,3,3-trifluoro-propane and a mono-or dichlorinated C₁ or C₃ alkane which are essentially constant boiling,environmentally acceptable and which remain liquid at room temperature.

DETAILED DESCRIPTION OF THE INVENTION

In accordance with the invention, novel azeotrope-like compositions of1-chloro-3,3,3-trifluoro-propane (HCFC-253eb) and a mono- ordichlorinated C₁ or C₃ alkane have been discovered wherein theazeotrope-like components of the composition consist of1-chloro-3,3,3-trifluoropropane and a mono- or dichlorinated C₁ or C₃alkane.

For purposes of this invention, the term "mono- or dichlorinated C₁ orC₃ alkane" shall refer to one of the following compounds:dichloromethane, 1-chloropropane and 2-chloropropane.

The HCFC-253eb component of the invention has good solvent properties.The chlorinated alkane also has good solvent capabilities; enhancing thesolubility of oils. Thus, when these components are combined ineffective amounts, an efficient azeotropic solvent results.

When 1-chloropropane is the chlorinated alkane, the azeotrope-likecompositions of the invention consist essentially of from about 93 toabout 56 weight percent HCFC-253eb and from about 7 to about 44 weightpercent 1-chloropropane and boil at about 44.4° C. ±0.5° C. at 760 mmHg.

In a preferred embodiment using 1-chloropropane, the azeotrope-likecompositions of the invention consist essentially of from about 87 toabout 60 weight percent HCFC-253eb and from about 13 to about 40 weightpercent 1-chloropropane.

In a more preferred embodiment using 1-chloropropane, the azeotrope-likecompositions of the invention consist essentially of from about 84 toabout 60 weight percent HCFC-253eb and from about 16 to about 40 weightpercent 1-chloropropane.

When 2-chloropropane is the chlorinated alkane, the azeotrope-likecompositions of the invention consist essentially of from about 99 toabout 92 weight percent HCFC-253eb and from about 1 to about 8 weightpercent 2-chloropropane and boil at about 35.6° C. ±0.3° C. at 760 mmHg.

In a preferred embodiment using 2-chloropropane, the azeotrope-likecompositions of the invention consist essentially of from about 99 toabout 93 weight percent HCFC-253eb and from about 1 to about 7 weightpercent 2-chloropropane.

In a more preferred embodiment using 2-chloropropane, the azeotrope-likecompositions of the invention consist essentially of from about 98.5 toabout 93.5 weight percent HCFC-253eb and from about 1.5 to about 6.5weight percent 2-chloropropane.

When dichloromethane is the chlorinated alkane, the azeotrope-likecompositions of the invention consist essentially of from about 98.4 toabout 50 weight percent HCFC-253eb and from about 1.6 to about 50 weightpercent dichloromethane and boil at about 39.2° C. ±0.5° C. at 760 mmHg.

In a preferred embodiment using dichloromethane, the azeotrope-likecompositions of the invention consist essentially of from about 97 toabout 55 weight percent HCFC-253eb and from about 3 to about 45 weightpercent dichloromethane.

In a more preferred embodiment using dichloromethane, the azeotrope-likecompositions of the invention consist essentially of from about 95 toabout 60 weight percent HCFC-253eb and from about 5 to about 40 weightpercent dichloromethane.

The precise or true azeotrope compositions have not been determined buthave been ascertained to be within the indicated ranges. Regardless ofwhere the true azeotropes lie, all compositions within the indicatedranges, as well as certain compositions outside the indicated ranges,are azeotrope-like, as defined more particularly below.

From fundamental principles, the thermodynamic state of a fluid isdefined by four variables: pressure, temperature, liquid composition andvapor composition, or P-T-X-Y, respectively. An azeotrope is a uniquecharacteristic of a system of two or more components where X and Y areequal at a stated P and T. In practice, this means that the componentsof a mixture cannot be separated during distillation, and therefore areuseful in vapor phase solvent cleaning as described above.

For purposes of this discussion, by azeotrope-like composition isintended to mean that the composition behaves like a true azeotrope interms of its constant-boiling characteristics or tendency not tofractionate upon boiling or evaporation. Such compositions may or maynot be a true azeotrope. Thus, in such compositions, the composition ofthe vapor formed during boiling or evaporation is identical orsubstantially identical to the original liquid composition. Hence,during boiling or evaporation, the liquid composition, if it changes atall, changes only minimally. This is contrasted with non-azeotrope-likecompositions in which the liquid composition changes substantiallyduring boiling or evaporation.

Thus, one way to determine whether a candidate mixture is"azeotrope-like" within the meaning of this invention, is to distill asample thereof under conditions (i.e. resolution-- number of plates)which would be expected to separate the mixture into its separatecomponents. If the mixture is non-azeotropic or non-azeotrope-like, themixture will fractionate, i.e., separate into its various componentswith the lowest boiling component distilling off first, and so on. Ifthe mixture is azeotrope-like, some finite amount of a firstdistillation cut will be obtained which contains all of the mixturecomponents and which is constant boiling or behaves as a singlesubstance. This phenomenon cannot occur if the mixture is notazeotrope-like, i.e., it is not part of an azeotropic system. If thedegree of fractionation of the candidate mixture is unduly great, then acomposition closer to the true azeotrope must be selected to minimizefractionation. Of course, upon distillation of an azeotrope-likecomposition such as in a vapor degreaser, the true azeotrope will formand tend to concentrate. Ebulliometric techniques may also be used todetermine azeotropy. Using this technique, the proportions of componentsin a composition are varied and their boiling points measured andrecorded. Using the maximum and minimum boiling points, the azeotropecan be determined. See Example 1.

It follows from the above that another characteristic of azeotrope-likecompositions is that there is a range of compositions containing thesame components in varying proportions which are azeotrope-like. Allsuch compositions are intended to be covered by the term azeotrope-likeas used herein. As an example, it is well known that at differentpressures, the composition of a given azeotrope will vary at leastslightly as does the boiling point of the composition. Thus, anazeotrope of A and B represents a unique type of relationship but with avariable composition depending on temperature and/or pressure.Accordingly, another way of defining azeotrope-like within the meaningof the invention is to state that mixtures of HCFC-253eb and1-chloropropane boil within ±0.5° C. (at 760 mm Hg) of the about 44.4°C.; mixtures of HCFC-253eb and 2-chloropropane boil within ±0.3° C. (at760 mm Hg) of the about 35.6° C.; and mixtures of HCFC-253eb anddichloromethane boil within ±0.5° C. (at 760 mm Hg) of the about 39.2°C. As is readily understood by persons skilled in the art, the boilingpoint of the azeotrope will vary with the pressure.

As stated above, the azeotrope-like compositions discussed herein areuseful as solvents for various cleaning applications including vapordegreasing, defluxing, cold cleaning, dry cleaning, dewatering,decontamination, spot cleaning, aerosol propelled rework, extraction,particle removal, and surfactant cleaning applications.

Thus, in one process embodiment, the azeotrope-like compositions of theinvention may be used to clean solid surfaces by treating said surfaceswith said compositions in any manner well known in the art such as bydipping or spraying or use of conventional degreasing apparatus.

When the present azeotrope-like compositions are used to clean solidsurfaces by spraying the surfaces with the compositions, preferably, theazeotrope-like compositions are sprayed onto the surfaces by using apropellant. Preferably, the propellant is selected from the groupconsisting of hydrocarbons, chlorofluoro-carbons,hydrochlorofluorocarbons, hydrofluorocarbons, dimethyl ether, carbondioxide, nitrogen, nitrous oxide, methylene oxide, air, and mixturesthereof.

Useful hydrocarbon propellants include isobutane, butane, propane, andmixtures thereof; commercially available isobutane, butane, and propanemay be used in the present invention. Useful chlorofluorocarbonpropellants include trichlorofluoromethane (known in the art as CFC-11),dichlorodifluoromethane (known in the art as CFC-12),1,1,2-trichloro-1,2,2-trifluoroethane (known in the art as CFC-113), and1,2-dichloro-1,1,2,2-tetra-fluoroethane (known in the art as CFC-114);commercially available CFC-11, CFC-12, CFC-113, and CFC-114 may be usedin the present invention.

Useful hydrochlorofluorocarbon propellants include dichlorofluoromethane(known in the art as HCFC-21), chlorodifluoromethane (known in the artas HCFC-22), 1-chloro-1,2,2,2-tetrafluoroethane (known in the art asHCFC-124), 1,1-dichloro-2,2-difluoroethane (known in the art asHCFC-132a), 1-chloro-2,2,2-trifluoroethane known in the art asHCFC-133), and 1-chloro-1,1-difluoroethane (known in the art asHCFC-142b); commercially available HCFC-21, HCFC-22, and HCFC-142b maybe used in the present invention. HCFC-124 may be prepared by a knownprocess such as that taught by U.S. Pat. No. 4,843,181 and HCFC-133 maybe prepared by a known process such as that taught by U.S. Pat. No.3,003,003.

Useful hydrofluorocarbon propellants include trifluoromethane (known inthe art as HFC-23), 1,1,1,2-tetrafluoroethane (known in the art asHFC-134a), and 1,1-difluoroethane (known in the art as HFC-152a);commercially available HFC-23 and HFC-152a may be used in the presentinvention. Until HFC-134a becomes available in commercial quantities,HFC-134a may be prepared by any known method such as that disclosed byU.S. Pat. No. 4,851,595. More preferred propellants includehydrochlorofluorocarbons, hydrofluorocarbons, and mixtures thereof. Themost preferred propellants include chlorodifluoromethane and1,1,1,2-tetrafluoroethane.

In another process embodiment, the azeotrope-like compositions of theinvention may be used to form polyurethane and polyisocyanurate foams byreacting and foaming a mixture of ingredients which will react to formpolyurethane and polyisocyanurate foams in the presence of a blowingagent comprising the azeotrope-like compositions.

The compositions of the invention may be used as auxiliary or primaryblowing agents for the preparation of polyurethane foams. Polyurethanesare polymers of polyols and isocyanates. A wide variety of polyols maybe employed as disclosed in the prior art, such as polyether polyols andpolyester polyols. Illustrative suitable polyether polyols arepolyoxypropylene diols having a molecular weight of between about 1,500and 2,500, glycerol based polyoxypropylene triols having a molecularweight of between about 1,000 and 3,000, trimethylolpropane-based triolshaving a hydroxyl number of about 390, sorbitol-based hexol having ahydroxyl number of about 490, and sucrose-based octols having a hydroxylnumber of about 410. Illustrative suitable polyester polyols are thereaction products of polyfunctional organic carboxylic acids such assuccinic acid, adipic acid, phthalic acid and terephthalic acid withmonomeric polyhydric alcohols such as glycerol, ethylene glycol,trimethylol propane, and the like. A wide variety of isocyanates may beemployed as disclosed in the prior art. Illustrative suitableisocyanates are the aliphatic isocyanates such as hexamethylenediisocyanate, aromatic isocyanates such as toluene diisocyanate (TDI),preferably the isomeric mixture containing about 80 weight percent ofthe 2,4 isomer and 20 weight percent of the 2,6 isomer, crude TDI, crudediphenylmethane diisocyanate and polymethylpolyphenyl isocyanate.

The amount of blowing agent to be employed will depend on whether it isto be used as a primary or auxiliary blowing agent and the nature of thefoams desired, i.e, whether flexible or rigid foam is desired.

The amount of blowing agent employed can be readily determined bypersons of ordinary skill in the art. Generally, about 1 to about 15weight percent based on the polyurethane forming reaction mixture isemployed and preferably, about 5 to about 10 weight percent.

As is well known in the art, the urethane-forming reaction requires acatalyst. Any of the well known urethane-forming catalysts may beemployed. Illustrative organic catalysts are the amino compounds such astriethylenediamine N,N,N',N'-tetramethylethylenediamine,dimethylethanolamine, triethylamine and N-ethylmorpholine. Inorganiccompounds such as the non-basic heavy metal compounds as illustrated bydibutyl tin dilaurate, stannous octoate and manganese acetyl acetonatemay also be used as catalysts. In general, the amount of catalystpresent in the foam forming mixture ranges from about 0.05 to about 2parts by weight per 100 parts by weight of the polyol component.

As is well recognized in the art, a variety of other additives may beincorporated in the foam-forming mixtures including stabilizers, such assilicone oils; cross-linking agents such as 1,4-butanediol, glycerol,triethanolamine methylenedianiline; plasticizers, such as tricresylphosphate and dioctyl phthalate; antioxidants; flame retardants;coloring material; fillers; and antiscorch agents.

Polyurethane foams are prepared according to the invention by reactingand foaming a mixture of ingredients which will react to form the foamsin the presence of a blowing agent according to the invention. Inpractice, the foam forming ingredients are blended, allowed to foam, andare then cured to a finished product. The foaming and curing reactions,and conditions therefor are well-known in the art and do not form a partof this invention. Such are more fully described in the prior artrelating to the manufacture of polyurethane foams. Thus, for example,the polyether may first be converted to a polyether-polyisocyanateprepolymer by reaction in one or more stages with an excess amount ofisocyanate at temperatures from about 75°-125° C. or by reacting thepolyol and the isocyanate together at room temperature in the presenceof a catalyst for the reaction such as N-methylmorpholine. Theprepolymer would then be charged to the foam-forming mixture as the foamproducing ingredient with or without the addition of additionalisocyanate and foamed in the presence of the blowing agent, optionallywith additional polyol cross-linking agents and other conventionaloptional additives. Heat may be applied to cure the foam. If aprepolymer is not employed, the polyether, isocyanate, blowing agent andother optional additives may be reacted simultaneously to produce thefoam in a single stage.

Aerosol products have employed individual halocarbons as well ashalocarbon blends as propellant vapor pressure attenuators, in aerosolsystems. Azeotropic mixtures, like those of the invention, with theirconstant compositions and vapor pressures would be very useful assolvents and propellants in aerosol systems.

The HCFC-253eb and chlorinated alkane components of the invention areknown materials. Preferably, they should be used in sufficiently highpurity so as to avoid the introduction of adverse influences upon thesolvent or constant boiling properties of the system.

Commercially available HCFC-253eb, dichloromethane, 1-chloropropane and2-chloropropane may be used in the present invention. The HCFC-253ebcomponent may be purchased, for example, from PCR Inc., of Gainsville,Fla. or Halocarbon Products Co. of Hackensack, N.J. Alternately, it maybe synthesized by reacting commercially available carbon tetrachlorideand ethylene at low temperature in the presence of hydrogen fluoride asa catalyst to form 1,1,1,3-tetrachloropropane. The hydrogen fluoridethen serves as a fluorination agent to convert the1,1,1,3-tetrachloropropane to 1-chloro-3,3,3-trifluoropropane.

Inhibitors may be added to the present azeotrope-like compositions toinhibit decomposition of the compositions; react with undesirabledecomposition products of the compositions; and/or prevent corrosion ofmetal surfaces. Any or all of the following classes of inhibitors may beemployed in the invention: epoxy compounds such as propylene oxide;nitroalkanes such as nitromethane; ethers such as 1-4-dioxane;unsaturated compounds such as 1,4-butane diol; acetals or ketals such asdipropoxy methane; ketones such as methyl ethyl ketone; alcohols such astertiary amyl alcohol; esters such as triphenyl phosphite; and aminessuch as triethyl amine. Other suitable inhibitors will readily occur tothose skilled in the art.

Having described the invention in detail and by reference to preferredembodiments thereof, it will be apparent that modifications andvariations are possible without departing from the scope of theinvention defined in the appended claims.

The present invention is more fully illustrated by the followingnon-limiting Examples.

EXAMPLE 1

The compositional range over which HCFC-253eb and dichloromethaneexhibit constant boiling behavior was determined. This was accomplishedby charging measured quantities of HCFC-253eb into an ebulliometer. Theebulliometer consisted of a heated sump in which the HCFC-253fb wasbrought to a boil. The upper part of the ebulliometer connected to thesump was cooled thereby acting as a condenser for the boiling vapors,allowing the system to operate at total reflux. After bringing theHCFC-253fb to a boil at atmospheric pressure, measured amounts (3 cc) ofdichloromethane were titrated into the ebulliometer. The change inboiling point was measured with a platinum resistance thermometer.

The results indicate that compositions of HCFC-253eb and dichloromethaneranging from 50-98.4/50-1.6 weight percent respectively would exhibitconstant boiling behavior at about 39.2° C. ±0.5° C. at 760 mm Hg.

EXAMPLE 2

The compositional range over which HCFC-253eb and 1-chloropropaneexhibit constant boiling behavior was determined by repeating theprocedure outlined in Example 1 above. The results indicate thatcompositions of HCFC-253eb and 1-chloropropane ranging from 56-93/44-7weight percent respectively would exhibit constant boiling behavior atabout 44.4° C. ±0.5° C. at 760 mm Hg.

EXAMPLE 3

The compositional range over which HCFC-253eb and 2-chloropropaneexhibit constant boiling behavior was determined by repeating theprocedure outlined in Example 1 above. The results indicate thatcompositions of HCFC-253eb and 2-chloropropane ranging from 92-99/8-1weight percent respectively would exhibit constant boiling behavior atabout 35.6° C. ±0.3° C. at 760 mm Hg.

EXAMPLES 4-6

Performance studies are conducted to evaluate the solvent properties ofthe azeotrope-like compositions of the invention. Specifically, metalcoupons are cleaned using the azeotrope-like composition of Example 1 assolvent (this experiment is repeated using the azeotrope-likecompositions of Examples 2 and 3. The metal coupons are soiled withvarious types of oils and heated to 93° C. so as to partially simulatethe temperature attained while machining and grinding in the presence ofthese oils.

The metal coupons thus treated are degreased in a simulated vapor phasedegreaser. Condenser coils are kept around the lip of a cylindricalvessel to condense the solvent vapor which then collects in the vessel.The metal coupons are held in the solvent vapor and rinsed for a periodof 15 seconds to 2 minutes depending upon the oils selected.

The cleaning performance of the azeotrope-like compositions isdetermined by visual observation and by measuring the weight change ofthe coupons using an analytical balance to determine the total residualmaterials left after cleaning. The results indicate that thecompositions of the invention are effective solvents.

EXAMPLES 7-9

For the following examples, six-ounce three-piece aerosol cans are used.The azeotrope-like composition of each of Examples 1-3 is weighed into atared aerosol can. After purging the can with tetrafluoroethane in orderto displace the air within the container, a valve is mechanicallycrimped onto the can. Liquid chlorodifluoromethane is then added throughthe valve utilizing pressure burettes.

A printed circuit board having an area of 37.95 square inches anddensely populated with dip sockets, resistors, and capacitors isprecleaned by rinsing with isopropanol before wave soldering. The boardis then fluxed and wave soldered using a Hollis TDL wave solder machine.

The printed circuit board is then spray cleaned using the aerosol canhaving the azeotrope-like composition therein. The cleanliness of theboard is tested visually and also using an Omega-meter which measuresthe ionic contamination of the board. The results indicate that theazeotrope-like compositions of the invention are effective cleaningagents.

EXAMPLES 10-12

Free-rise rigid polyurethane foam is prepared from the formulationspecified in Table V using a Martin Sweets Co. Modern Module IIIurethane foam machine at a delivery rate of 15 lbs./min. and by usingthe azeotrope-like composition of Example 1 as blowing agent (thisexperiment is repeated using the compositions of Examples 2 and 3). Thispolyurethane formulation is one example of a pour-in-place rigidpolyurethane formulation which might be used as appliance insulation.

                  TABLE V                                                         ______________________________________                                                  RIGID POLYURETHANE FORMULATION                                      Component             Parts by weight                                         ______________________________________                                        Pluracol 1114.sup.1 (420-OH#)                                                                       100.0                                                   Silicone L-5340.sup.2 1.5                                                     Thancat TD-33.sup.3   0.5                                                     Thancat DME.sup.4     0.2                                                     Catalyst T-12.sup.5   0.1                                                     HCFC-253eb/C.sub.1 or C.sub.3 alkane (50/50)                                                        30.0                                                    Lupranate M20S.sup.6 (1.29 Index)                                                                   129.0                                                   ______________________________________                                         .sup.1 BASF Wyandotte Corp.  polyether polyol                                 .sup.2 Union Carbide Corp.  silicone surfactant                               .sup.3 Texaco Inc.  33% triethylene diamine in propylene glycol               .sup.4 Texaco Inc.  N,Ndimethylethanolamine                                   .sup.5 Metal & Thermit Co.  dibutyl dilaurate                                 .sup.6 BASF Wyandotte Corp.  polymethylene polyphenylisocyanate          

What is claimed is:
 1. Azeotrope-like compositions consistingessentially of from about 98.4 to about 50 weight percent1-chloro-3,3,3-trifluoropropane and from about 1.6 to about 50 weightpercent dichloromethane which boil at about 39.2° C. at 760 mm Hg; orfrom about 93 to about 56 weight percent 1-chloro-3,3,3-trifluoropropaneand from about 7 to about 44 weight percent 1-chloropropane which boilat about 44.4° C. at 760 mm Hg; or from about 99 to about 92 weightpercent 1-chloro-3,3,3-trifluoropropane and from about 1 to about 8weight percent 2-chloropropane which boil at about 36.5° C. at 760 mmHg; wherein the azeotrope-like components of the composition consist of1-chloro-3,3,3-trifluoropropane and either dichloromethane,1-chloropropane or 2-chloropropane.
 2. The azeotrope-like compositionsof claim 1 wherein said compositions of 1-chloro-3,3,3-trifluoropropaneand dichloromethane boil at 39.2° C. ±about 0.5° C. at 760 mm Hg.
 3. Theazeotrope-like compositions of claim 1 wherein said compositions consistessentially of from about 97 to about 55 weight percent1-chloro-3,3,3-trifluoropropane and from about 3 to about 45 weightpercent dichloromethane.
 4. The azetrope-like compositions of claim 3wherein said compositions consist essentially of from about 95 to about60 weight percent 1-chloro-3,3,3-trifluoropropane and from about 5 toabout 40 weight percent dichloromethane.
 5. The azeotrope-likecompositions of claim 1 wherein said compositions of1-chloro-3,3,3-trifluoropropane and 1-chloropropane boil at 44.4° C.±about 0.5° C. at 760 mm Hg.
 6. The azeotrope-like compositions of claim1 wherein said compositions consist essentially of from about 87 toabout 60 weight percent 1-chloro-3,3,3-trifluoropropane and from about13 to about 40 weight percent 1-chloropropane.
 7. The azetrope-likecompositions of claim 6 wherein said compositions consist essentially offrom about 84 to about 60 weight percent 1-chloro-3,3,3-trifluoropropaneand from about 16 to about 40 weight percent 1-chloropropane.
 8. Theazetrope-like compositions of claim 1 wherein said compositions of1-chloro-3,3,3-trifluoropropane and 2-chloropropane boil at 35.6° C.±about 0.3° C. at 760 mm Hg.
 9. The azeotrope-like compositions of claim1 wherein said compositions consist essentially of from about 99 toabout 93 weight percent 1-chloro-3,3,3-trifluoropropane and from about 1to about 7 weight percent 2-chloropropane.
 10. The azeotrope-likecompositions of claim 9 wherein said compositions consist essentially offrom about 98.5 to about 93.5 weight percent1-chloro-3,3,3-trifluoropropane and from about 1.5 to about 6.5 weightpercent 2-chloropropane.
 11. The azeotrope-like compositions of claim 1wherein an effective amount of an inhibitor is present in saidcompositions to accomplish at least one of the following functions: toinhibit decomposition of the compositions; react with undesirabledecomposition products of the compositions; and prevent corrosion ofmetal surfaces.
 12. The azeotrope-like compositions of claim 11 whereinsaid inhibitor is selected from the group consisting of epoxy compounds,nitroalkane, acetals, ketals, ketones, alcohols, esters and amines. 13.A method of cleaning a solid surface comprising treating said surfacewith an azeotrope-like composition of claim
 1. 14. A process forpreparing a polyurethane or polyisocyanurate foam comprising reactingand foaming a mixture of ingredients which will react to form thepolyurethane or polyisocyanurate foam in the presence of at least oneblowing agent according to claim
 1. 15. An aerosol compositioncomprising a propellant and an active agent, wherein the propellant isan azeotrope-like composition of claim 1.